import java.util.Scanner;

public class a022_迴文 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String input, output;
		
		boolean palindrome;
		
		char each_str1, each_str2;
		
		while(sc.hasNext()) {
			input = sc.nextLine();
			
			palindrome = true;
			
			for(int i = 0; i < input.length() / 2; i++) {
				each_str1 = input.charAt(i);
				each_str2 = input.charAt(input.length() - 1 - i);
				
				if(each_str1 != each_str2)
					palindrome = false;
			}
			
			if(palindrome)
				System.out.println("yes");
			else
				System.out.println("no");
		}
	}
	
}